Hi, On the ICE train on Hauptstrecke München - Augsburg Route Add-On when out of a seat and walking around the train the sound inside the train sounds like there is the wind blowing through as if you're in an outside view but louder, the train however when you sit down the sound changes and feels normal. The other ICE on Schnellfahrstrecke Köln-Aachen did not have this odd wind sound in the train. Hope this makes sense.
